Such identities neither confer nor require particular philosophical commitments or obligations.
This view that a 'theory' of knowledge is impossible has its analogue in Prichard's later argument that there can be no philosophical account of moral obligation of the sort that moral philosophers have traditionally tried to provide.
Plato's Crito is noteworthy not only as the first philosophical exploration of political obligation but also as the last to appear for centuries.
Although the lines that separate one theory from another are not always distinct, philosophical justifications of political obligation nowadays usually take the form of arguments from consent, gratitude, fair play, membership, or natural duty.
The case of how an agent may be said to acquire moral obligations involuntarily is particularly important in philosophical consideration of present day obligations arising from historic injustice.
In Part III the focus is on the skeptics, with particular attention to the self-proclaimed philosophical anarchists, who deny that political obligations exist yet do not want to abolish the state.
(See Kelsen 1967, 46 50; cf. Finnis 1979, 250) It may affirm our confidence in the obligation-correlative view to know that from earliest times philosophical reflection on political authority has focussed on the obligation to obey.
Some of these attempts apply specifically to Wolff's a priori attack on political authority and obligation, while others apply to philosophical anarchism in general.
This kind of humanism was given a more elaborate philosophical content by the English philosopher T.H. Green, whose Lectures on the Principles of Political Obligation (1885) greatly influenced members of the Liberal Party in the British governments of the period 1906 15.
The volume opens up important philosophical questions about our place in, and obligations to, a more-than-human world.
At present, though, no single theory has the support of all of those who continue to believe in political obligation, let alone the assent of philosophical anarchists.
